AlmaLinux 9 ARM64

Option A: Azure Portal

• Open the Azure Marketplace and search for "AlmaLinux 9 Arm64 SecureAnyCloud".
• Select the image and click Create.
• Configure the basics:
• Subscription: select your Azure subscription.
• Resource Group: create a new group or select an existing one.
• Virtual Machine Name: enter a name for your VM.
• Region: select your preferred Azure region.
• Size: select an Arm64 size. Standard_D2ps_v6 is recommended.
• Under Administrator Account, select SSH public key and enter your key.
• Under Inbound Port Rules, allow SSH (port 22).
• Click Review + Create, then Create.

Option B: Azure CLI

Run this command on your own workstation. Substitute your resource group, VM name and preferred region:

az vm image terms accept --urn sac1647283583153:almalinux-9-arm64:default:latest
az vm create \
  --resource-group myResourceGroup \
  --name my-almalinux-9-arm64-vm \
  --image sac1647283583153:almalinux-9-arm64:default:latest \
  --size Standard_D2ps_v6 \
  --admin-username azureuser \
  --generate-ssh-keys \
  --public-ip-sku Standard

The --size must be an Arm64 family (Standard_D2ps_v6 above). Azure rejects an x86 size for an Arm image at create time.

Run these commands on your own workstation, not on the VM. Find the public IP, then connect:

az vm show --resource-group myResourceGroup --name my-almalinux-9-arm64-vm --show-details --query publicIps -o tsv ssh azureuser@<vm-ip>

There is no password to enter. If SSH asks for one, your client is not offering the key that you supplied at create time.

Check that the machine is AlmaLinux 9 and that it is running on Arm.

cat /etc/almalinux-release

AlmaLinux release 9.8 (Olive Jaguar)

The os-release fields carry the same information in a machine-readable form, which is what configuration management tools read:

grep -E '^(NAME|VERSION|ID|VERSION_ID|PLATFORM_ID)=' /etc/os-release

NAME="AlmaLinux" VERSION="9.8 (Olive Jaguar)" ID="almalinux" VERSION_ID="9.8" PLATFORM_ID="platform:el9"

The distribution itself declares the RHEL compatibility lineage:

cat /etc/redhat-release

AlmaLinux release 9.8 (Olive Jaguar)

Check the kernel, which shows the architecture:

uname -srm

Linux 5.14.0-687.36.1.el9_8.aarch64 aarch64

The aarch64 value from uname confirms that this is the native 64-bit Arm build, not an emulated or x86 image. The version reported is the AlmaLinux 9 point release that the image was patched to. This listing tracks the 9 major release, so dnf update rolls it forward across future point releases.

Every available update was applied when this image was built. dnf check-update exits with 100 when updates are pending and 0 when none are:

dnf -q check-update >/dev/null 2>&1; echo "exit=$?"

exit=0

No reboot is pending either:

dnf needs-restarting -r

No core libraries or services have been updated since boot-up. Reboot should not be necessary.

Your update path is intact because the base repositories are enabled:

dnf repolist --enabled

repo id repo name appstream AlmaLinux 9 - AppStream baseos AlmaLinux 9 - BaseOS extras AlmaLinux 9 - Extras

CRB (CodeReady Builder) ships configured but disabled, which is the AlmaLinux default. Enable CRB only if you build software that needs its development headers:

sudo dnf config-manager --set-enabled crb

Automatic updates

Unlike a stock AlmaLinux cloud image, this machine keeps patching itself. dnf-automatic is installed and its timer is enabled, so the machine applies updates on its own schedule. Check the timer:

systemctl is-enabled dnf-automatic.timer

enabled

systemctl cat dnf-automatic.timer | grep -E 'OnCalendar|RandomizedDelaySec'

OnCalendar=*-*-* 6:00 RandomizedDelaySec=60m

The policy applies all available updates, not only those tagged as security errata. It never reboots automatically, so a kernel update waits for a maintenance window that you choose instead of restarting the machine without warning. Check the policy:

grep -E '^(apply_updates|upgrade_type|download_updates|reboot)' /etc/dnf/automatic.conf

upgrade_type = default download_updates = yes apply_updates = yes reboot = never

upgrade_type is deliberately default rather than security. On an image whose errata metadata is not always populated, a security-only policy can silently resolve to applying nothing, so default is the setting that keeps the machine current.

Because reboot = never, check periodically whether a restart is owed after a kernel update, using the needs-restarting -r command above. To opt out entirely, run sudo systemctl disable --now dnf-automatic.timer.

Confirm that SELinux is enforcing:

getenforce

Enforcing

Confirm that the root account is locked. LK in the second field means locked:

passwd -S root

root LK 2009-12-22 -1 -1 -1 -1 (Alternate authentication scheme in use.)

Confirm that no account on the machine has a usable password. This prints nothing on a clean image:

sudo awk -F: '($2 !~ /^[!*]/) && ($2 != "") {print $1}' /etc/shadow

Read the SSH daemon's effective policy rather than the config file, because the running daemon is what a client meets:

sudo sshd -T | grep -E '^(permitrootlogin|passwordauthentication|pubkeyauthentication) '

permitrootlogin without-password pubkeyauthentication yes passwordauthentication no

There is no swap on the operating system disk. Azure manages swap on the ephemeral resource disk if you want it, and Marketplace images cannot include a baked-in swap file. This command prints nothing:

swapon --show

Confirm what is listening. On a freshly launched machine, sshd on port 22 provides your remote access. The base OS also runs rpcbind on port 111 and chronyd bound to the loopback address for time synchronization:

ss -tulnH | awk '{print $1, $5}' | sort -u

tcp 0.0.0.0:111 tcp 0.0.0.0:22 tcp [::]:111 tcp [::]:22 udp 0.0.0.0:111 udp 127.0.0.1:323 udp [::1]:323 udp [::]:111

The Azure Network Security Group (NSG) controls inbound traffic. Only the ports that you explicitly open in the NSG are reachable from outside the VM, regardless of what is bound locally. If you do not use RPC-based services and want to close port 111 on the host as well, run sudo systemctl disable --now rpcbind.socket rpcbind.service.

The Azure Linux Agent handles provisioning, extensions and the portal's serial console:

systemctl is-active waagent rpm -q WALinuxAgent cloud-init chrony

active WALinuxAgent-2.14.0.1-4.el9.noarch cloud-init-24.4-8.el9_8.1.alma.1.noarch chrony-4.8-1.el9.aarch64

cloud-init should report done, which means provisioning finished cleanly:

cloud-init status

status: done

The kernel puts a console on ttyAMA0, the Arm PL011 serial port. This makes boot diagnostics and the portal's serial console work when you cannot reach the machine over SSH. On x86 images the console is ttyS0, and on Arm it is ttyAMA0.

grep -o 'console=ttyAMA0[^ ]*' /proc/cmdline

Time synchronization runs through chronyd against the Azure host clock:

chronyc -n sources | head -4

MS Name/IP address Stratum Poll Reach LastRx Last sample =============================================================================== #* PHC0 2 3 377 8 -5662ns[-8956ns] +/- 3607ns

Azure attaches an ephemeral resource disk, which waagent formats and mounts at /mnt. The disk is fast and local, and it is erased whenever the machine is deallocated or moved. Use it for scratch data and caches, never for data you need to keep:

df -h / /mnt

Filesystem Size Used Avail Use% Mounted on /dev/sda4 29G 1.4G 28G 5% / /dev/sdb1 7.8G 28K 7.4G 1% /mnt

The Azure Network Security Group (NSG) controls inbound and outbound traffic. It is the first place to open a port, and usually the only place you need to.

This image is a minimal build, so firewalld is not installed. Confirm it:

rpm -q firewalld || echo "(firewalld absent - the Azure NSG is your only firewall)"

package firewalld is not installed (firewalld absent - the Azure NSG is your only firewall)

This is deliberate. With no host firewall in the way, your NSG rules take effect exactly as written, with no second layer to keep in sync. Confirm what is listening before you open anything:

ss -tlnp

If your policy also requires a host firewall, install and enable it yourself:

sudo dnf install -y firewalld
sudo systemctl enable --now firewalld
sudo firewall-cmd --permanent --add-port=443/tcp sudo firewall-cmd --reload

Once firewalld is running, open each port in both the Azure NSG and firewalld before traffic can reach your service.

AppStream carries the application packages. Search it, then install what you need:

dnf search nginx

Install a package and enable it in the usual way, for example sudo dnf install -y nginx followed by sudo systemctl enable --now nginx. Everything in the repositories is built for Arm, so dnf resolves aarch64 packages automatically. You do not need to configure anything for the architecture.

To add another administrator, create the account with sudo adduser <name> and add it to the wheel group with sudo usermod -aG wheel <name>. Then copy your public key into /home/<name>/.ssh/authorized_keys. Set mode 600 on the file and mode 700 on the .ssh directory, both owned by that user.

The image ships with no human accounts, so azureuser is the only login until you add one:

getent group wheel